# Why do ionic solids NOT dissolve in water?

$\text{Sodium hydroxide}$, $\text{sodium carbonate}$, $\text{sodium biphosphate}$, $\text{sodium fluoride}$, are all crystalline materials. And they dissolve in aqueous solutions to give quantities of $H {O}^{-}$. In the case of $N a O H$, the quantity is stoichiometric. Ammonia, $N {H}_{3}$, exists as a gas before dissolution in water.